Apple's yearly developer conference should see iOS 8, OS X 10.10, and likely some hardware.
Apple Boosts iPhone 5s Battery Capacity by 10%, iPhone 5c by 5% Over iPhone 5
In particular, both new iPhones offer up to 10 hours of talk time on 3G and the same 10 hours of LTE Internet use, up from 8 hours for both tasks on the iPhone 5. Standby time on the two new models has also increased to up to 250 hours compared to 225 hours on the iPhone 5.
Apple has not, however, revealed the exact battery capacity for the new iPhones, but AnandTech dug into the FCC documents and discovered that the iPhone 5c carries 5% higher battery capacity than the iPhone 5, while the iPhone 5s carries a 10% larger battery.
While I'm somewhat skeptical sometimes of the accuracy of battery capacities as reported in FCC disclosures (which I noted about the battery size for the Nexus 5), these numbers seem credible given what I've heard, the statement Apple made during the keynote about the 5C battery size going up, and what I'd expect with some board re-layout for the 5S.The iPhone 5s number reported in the FCC documents is close but not identical to what was seen on a leaked December 2012 prototype. The battery in that device was listed as 5.92 Whr, while the FCC documents report a capacity of 5.96 Whr.
The documents report a capacity of 5.73 Whr for the iPhone 5c battery, which matches that seen in photos of the part posted by C Technology today.
Pre-orders for the iPhone 5c begin at 12:01 AM Pacific Time tomorrow morning, with availability of both the iPhone 5s and 5c set for Friday, September 20. Apple is not offering pre-orders for the iPhone 5s.